Distillate hydrocarbon fuel oil compositions with anti-corrosion properties

ABSTRACT

AN ADDITIVE WHICH, WHEN INCORPORATE IN A DISTILLATE HYDROCARBON FUEL OIL, IMPARTS TO SAID FUEL OIL COMPOSTION ANTI-CORROSION PROPERTIES, AND THE DISTILLATE HYDROCARBON FUEL OIL COMPOSITION CONTAINING SAID ADDITIVE. THE ADDITIVE IS COMPRISED OF A DYNERGISTIC MIXTURE OF (A) A DIAMIDE OBTAINED BY CONDENSING ONE MOLE OF A DICARBOXYLIC ACID WITH TWO MOLES OF AN N,N-DIALKYL HYDROCARBYLENEDIAMINE A DICARBOXYLIC ACID WITH ONE MOLE OF A HYDROCARBYLENEDIAMINE HAVING AN AROMATIC HYDROCARBON SUBSTITUENT ON ONE AMINO NITROGEN AND ONE MOLE OF A HYDROCARBYLENEDIAMINE WHEREIN ONE OF THE AMINO NITROGENS IS PART OF A HETEROCYCLIC RING.

United States Patent O assignors to Cities Service Oil Company, New York,

.Y. No Drawing. Filed Mar. 2, 1970, Ser. No. 15,913 Int. Cl. Cl 1/18, 1/22 US. Cl. 44-63 13 Claims ABSTRACT OF THE DISCLOSURE An additive which, when incorporated in a distillate hydrocarbon fuel oil, imparts to said fuel oil composition anti-corrosion properties, and the distillate hydrocarbon fuel oil composition containing said additive. The additive is comprised of a synergistic mixture of (a) a diamide obtained by condensing one mole of a dicarboxylic acid with two moles of an N,N-dialkyl hydrocarbylenediamine and (b) a diamide obtained by condensing one mole of a dicarboxylic acid with one mole of a hydrocarbylenediamine having an aromatic hydrocarbon substituent on one amino nitrogen and one mole of a hydrocarbylenediamine wherein one of the amino nitrogens is part of a heterocyclic ring.

BACKGROUND OF THE INVENTION The prevention of metal corrosion is an ever-present problem. The electrochemical theory of corrosion postulates that a metal surface may acquire potentials locally and that these depend upon the reactions occurring in the vicinity. When iron is immersed in an electrolyte such as an acid, miniature, local galvanic cells are formed with the more anodic potentials induced where the metal goes into solution. Reduction of hydrogen ion or oxygen, occurring elsewhere, induces the more cathodic potentials. Continued attack of the metal may be stopped if either reaction is stifled. Certain materials, both inorganic and organic, when added to the metal-fluid system, are known to retard the rate of metal dissolution. Some of these influence the cathode reaction predominately and some exert the main effect on the anode reaction.

Evidence that organic inhibitor action is a process Which involves adsorption is abundant. Therefore, factors which relate molecular structure to adsorbability and to type of forces involved between metal and inhibitor are important. Molecular weight, solubility, type of functional group, number of functional groups, dimensions of the molecule, dipole moment, degree of association and reactivity are factors which relate to inhibitor effectiveness.

It is believed that organic inhibitors give rise to a film over the entire metal surface and that this has a very high electrical resistance. The film can be considered as a barrier which simply retards diffusion of the metal.

It has been proposed that adsorption of the inhibitor is general and that inhibitor action results from (a) increased resistance to current flow caused by a barrier of physically adsorbed inhibitor over most of the surface, and (b) by reduction in metal reactivity by chemisorbed inhibitor. The relative contribution of the two depends upon the inhibitor. It is postulated that the binding responsible for chemisorption is the formation of a dative bond between the metal and the organic molecule. The bond is formed from sharing a pair of electrons between the inhibitor and the metal.

In addition to adsorption, inhibitor action may also involve sequestering of ions, e.g., hydrogen ions and metal ions, in solution. By tying up these cations in chelate compounds, the transfer of electrons is diminished and 'ice oxidative corrosion is reduced. In general, therefore, inhibitors appear to act both as chelating agents and as film formers.

Prior art anti-corrosion additives for distillate hydrocarbon fuels aregenerally surface active agents. These include such materials as long chain fatty acids, long chain amines and their simple salts, quaternary salts of long chain amines, metal salts of high molecular weight organic sulfonates and nonionic surfactants such as polyvinyl alcohol and condensates of ethylene oxide and high molecular weight amines.

SUMMARY OF THE INVENTION It is an object of this invention to provide anti-corrosion additives suitable for incorporation in distillate hydrocarbon fuel oils.

It is another object of this invention to provide distillate hydrocarbon fuel oil compositions having excellent anticorrosion properties.

Still other objects will apear hereinafter.

The foregoing objects are attained in accordance with this invention. In general, this invention comprises a distillate hydrocarbon fuel oil composition containing:

(a) a major proportion of a distillate hydrocarbon fuel;

and (b) a minor proportion of an anti-corrosion additive comprising:

(1) a diamide having the formula 1)z 2)- 1] 2)' 1)z wherein R is alkyl, R is a hydrocarbylene of 1 to 10 carbons and D is a hydrocarbylene of 3 to 45 carbons;

and

(2) a diamide having the formula wherein Ar and Ar are selected from the group consisting of aryl, alkaryl, and aralkyl and additionally one of Ar or Ar is hydrogen, R is a hydrocarbylene of 1 to 10 carbons, D is a hydrocarbylene of 3 to 45 carbons, R is a hydrocarbylene of 1 to 10 carbons and is selected from the group consisting of 5 and 6 membered heterocyclic rings containing 2 ring nitrogens;

and an anti-corrosion additive composition for distillate hydrocarbon fuel oils comprising the mixture of diamides (1) and (2) above.

Distillate hydrocarbon fuel oil compositions containing the synergistic additive mixtures of this invention exhibit remarkable anti-corrosion properties. Due to the synergism exhibited by the additive mixtures of this invention, satisfactory anti-corrosion properties are achieved at low concentration levels of additive. Thus these additives are also attractive from an economic viewpoint. Other advantages of this invention will be apparent from the following description.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The distillate hydrocarbon fuel oil compositions of this invention are prepared by incorporating into a major proportion of a distillate hydrocarbon fuel oil a minor proportion of an additive comprising a synergistic mixture of (1) a diamide obtained by condensing 1 mole of a dicarboxylic acid of about 5 to 47 carbons with 2 moles of an N,N-dialkyl hydrocarbylenediamine and (2) a diamide obtained by condensing 1 mole of a dicarboxylic acid of about 5 to 47 carbons with 1 mole of an N-hydrocarbyl hydrocarbylenediamine wherein the N-hydrocarbyl may by aryl, alkaryl, or aralkyl and 1 mole of a hydrocarbylenediamine in which one of the amino nitrogens is part of a heterocyclic ring. Examples of the distillate hydrocarbon fuels that have anti-corrosion properties imparted thereto by the additives of this invention are No. 2 fuel oil, diesel fuels and jet fuels.

The dicarboxylic acids that are condensed with 2 moles of N,N-dialkyl hydrocarbylenediamine contain about 5 to 47 carbons. The hydrocarbylene portion of the acid may be aliphatic, naphthenic or aromatic or it may contain various mixtures of aliphatic, naphthenic and aromatic segments. The aliphatic and naphthenic segments of the dicarboxylic acid may be saturated or unsaturated. While the dicarboxylic acid may contain from about 5 to 47 carbons, it is preferred that the acid contain about 10 to about 40 carbons. Examples of suitable dicarboxylic acids are glutaric acid, adipic acid, pimelic acid, 2-hexylterephthalic acid, 1,18-dicarboxyoctadecane, 1,4-cyclohexane dicarboxylic acid, 1,4-dicarboxy-Z-decylcyclohex-S-ene, and 1,8-dicarboxyct-4-ene. A particularly suitable acid has been found to be dimer acid which results from the controlled dimerization of unsaturated l8-carbon monocarboxylic fatty acids. The structure of dimer acid is not known with certainty but is believed to contain unsaturation.

The hydrocarbylene portion of the N,N-dialky1 hydrocarbylenediamine that is condensed with the dicarboxylic acid may contain about 1 to 10 carbons and may be aliphatic, naphthenic, aromatic or contain various mixtures of aliphatic, naphthenic and aromatic segments. Aliphatic and naphthenic segments may be saturated or unsaturated. It is preferred that the hydrocarbylene portion contain about 2 to 8 carbons. The N-alkyl groups of the N,N-dialkyl hydrocarbylenediamine may contain from 1 to about carbons and may be branched or straight chain. The N-alkyl groups may be either saturated or unsaturated and they may be the same or different. Examples of suitable N,N-dialkyl hydrocarbylenediamines are N,N-diisopropyl-p-phenylenediamine; N-methyl-N- butyl ethylenediamine; N,N-dipentenyl decylenediamine; N,N-diethyl octenylenediamine; N,N-dimethyl 1,4-diaminocyclohexane; and N,N-dibutyl 1,4-diamino-2-ethylcyclohex-S-ene. A particularly suitable diamine is N,N-dimethyl propylenediamine.

Suitable diamides obtained by condensing 1 mole of a dicarboxylic acid with 2 moles of an N,N-dialkyl hydrocarbylenediamine may thus be obtained by condensing 1 mole of any of the following dicarboxylic acids with 2 moles of any of the following diamines:

Dicarboxylic acids glutaric acid adipic acid pimelic acid 2-hexylterephthalic acid 1,4-cyclohexane dicarboxylic acid 1,4-dicarboxy-2-decylcyclohex-S-ene 1,8-dicarboxyoct-4-ene 1,18-dicarboxyoctadecane dimer acid N,N-dialkyl hydrocarbylenediamines ing 1 mole of dimer acid with 2 moles of N,N-dimethyl propylenediamine.

The dicarboxylic acids that are condensed with 1 mole of an N-hydrocarbyl hydrocarbylenediamine and 1 mole of a hydrocarbylenediamine in which one of the amino nitrogens is part of a heterocyclic ring are selected from the same group of dicarboxylic acids as described above. Dimer acid is preferred.

The hydrocarbylene portions of the N-hydrocarbyl hydrocarbylenediamines that are condensed with the above dicarboxylic acids contain about 1 to 10 carbons and preferably about 2 to 8 carbons. The hydrocarbylene portions of these diamines are selected from the same group of hydrocarbylene moieties as described above for the N,N-dialkyl hydrocarbylenediamines. The N-hydrocarbyl groups of the N-hydrocarbyl hydrocarbylenediamine may be aryl, alkaryl or aralkyl and may contain from about 6 to 30 carbons. Either amino group of the N-hydrocarbyl hydrocarbylenediamine may react with the carboxyl group of the acid, and mixtures are probably formed. Examples of suitable N-hydrocarbyl hydrocarbylenediamines are N-benzyl butylenediamine; N-naphthyl p-phenylenediamine; N-p-tolyl nonenylenediamine; N-phenyl hexylenediamine; N-p-dodecylphenyl hexylenediamine; N-benzyl 1,4-diaminocyclohex-2-ene; and N-phenyl 1,4-diaminocyclohexane. An especially suitable diamine is N-phenyl propylenediamine.

The hydrocarbylene portions of the hydrocarbylenediamines in which one of the amino nitrogens is part of a heterocyclic ring contain about 1 to 10 carbons and preferably about 2 to 8 carbons. The hydrocarbylene portions of these diamines are selected from the same group of hydrocarbylene moieties as described above for the other hydrocarbylenediamines. One of the amino groups of these diamines is part of a 5 or 6 membered heterocyclic ring containing 2 ring nitrogens. Examples of these hydrocarbylenediamines are N-( 8-aminooctyl) imidazole; N-(Z-aminoethyl) pyrazole; N-(lO-aminodecyl) imidazoline; N-(p-aminophenyl) tetrahydropyrimidine; N-(4- aminoryclohexyl) hexahydropyrimidine. The preferred diamine is N-(3-aminopropyl) piperazine.

Suitable diamides obtained by condensing 1 mole of a dicarboxylic acid with 1 mole of a N-hydrocarbyl hydrocarbylenediamine and 1 mole of a hydrocarbylenediamine in which one of the amino nitrogens is part of a heterocyclic ring may thus be obtained by condensing 1 mole of any of the following dicarboxylic acids with 1 mole of a diamine from each of the following two classes of diamines.

Dicarboxylic acids glutaric acid adipic acid pimelic acid Z-hexylterephthalic acid 1,4-cyclohexane dicarboxylic acid 1,4-dicarboxy-2-decylcyclohex-S-ene 1,8-dicarboxyoct-4-ene 1,18-dicarboxyoctadecane dimer acid N-hydrocarbyl hydrocarbylenediamines N-benzyl 'butylenediamine N-naphthyl p-phenylenediamine N-p-tolyl nonenylenediamine N-phenyl hexylenediamine N-p-dodecylphenyl hexylenediamine N-ibenzyl-l,4-diaminocyclohex-2-ene N-phenyl 1,4-diaminocyclohexane N-phenyl propylenediamine Hydrocarbylenediamines containing a heterocyclicring N-(S-aminooctyl) imidazole N-(Z-aminoethyl) pyrazole N-( IO-aminodecyl) imidazoline N (p-aminophenyl) tetrahydropyrimidine N- 4-aminocyclohexyl) hexahydropyrimidine N- (3-aminopropyl) piper-azine An especially suitable diamide is obtained by condensing 1 mole of dimer acid with 1 mole of N-phenyl propylenediamine and 1 mole of N-(3-aminopropyl) piperazine.

The distillate hydrocarbon fuel oil compositions of this invention contain from about 0.5 to about 8 pounds per thousand barrels (PTB) of our novel synergistic additive mixture. The distillate hydrocarbon fuel oil compositions of our invention preferably contain about 1 to about PTB of synergistic additive mixture.

The ratio by weight of the two diamides in the additive mixture may vary over a wide range. Thus the ratio by weight of the diamide formed by condensing 1 mole of a dicarboxylic acid with 2 moles of a N,N-dialkyl hydrocarbylenediamine to the diamide formed by condensing 1 mole of a dicarboxylic acid with 1 mole of a N-hydrocarbyl hydrocarbylenediamine and 1 mole of a hydrocarbylenediamine in which one of the amino nitrogens is part of a heterocyclic ring may be from about 1:10 to about :1 and preferably from about 1:4 to about 4:1. A particularly advantageous weight ratio is from about 1:2 to about 2:1.

The efficacy of our synergistic additive mixture in imparting anti-corrosion properties to distillate hydrocarbon fuel oil compositions was determined by subjecting distillate hydrocarbon fuel oil compositions to the Colonial Pipe Line Rust Test. The test is carried out as follows:

Colonial Pipe Line Rust Test Into a beaker is placed 300 ml. of the distillate hydrocarbon fuel oil composition to be tested and the stirred oil composition is heated to 100 F. A steel test specimen is inserted into the stirred, heated oil composition where it remains for 30 minutes to insure complete Wetting of the steel specimens by the oil composition. To the stirred oil composition are added 30 ml. of distilled water. The mixture is stirred at 100 F. for an additional 3.5 hours. The steel specimen is then removed, allowed to drain and then washed with precipitation naphtha or isooctane. The percent of the surface of the steel test specimen that is covered by rust is determined. The results are expressed as follows:

Rating: Percent of surface rusted A None. 'B++ Less than 0.1%. B+ Less than 5%. B p 5 to 25%. C 26- to 50%. D 51 to 75%. E 76 to 100%.

The following specific examples will serve to further illustrate our invention.

EXAMPLE I A series of No. 2 fuel oil compositions is prep-ared containing diamides of this invention singly and in combination. These compositions, and a blank containing no additive, are subjected to the Colonial Pipe Line Rust Test. One diamide, designated as (a), is a condensation product of 1 mole of dimer acid and 2 moles of N,N- dimethyl propylenediamine. The other diamide, designated as (b), is a condensation product of 1 mole of dimer acid, 1 mole of N-phenyl propylenediamine and 1 mole of N-(3-aminopropyl) piperazine. The concentrations of the additives in the No. 2 fuel compositions in pounds per thousand barrels of composition (PTB) and the results of the rust test are given in Table I.

The data in Table I illustrate the synergism exhibited by anti-corrosion additives comprised of the two classes of diamides of our invention.

EXAMPLE II A diesel fuel composition containing 2.5 PTB of the condensation product of 1 mole of glutaric acid and 2 moles of N,N-diethyl octenylenediamine (c) and 2.5 PTB of the condensation product of 1 mole of 1,4-cyclohexane dicarboxylic acid, 1 mole of N-benzyl butylenediamine and 1 mole of N-(IO-aminodecyl) imidazoline (g) is prepared and subjected to the Colonial Pipe Line Rust Test. The steel test piece exhibits less surface rust than is the case with tests run on comparable diesel fuel compositions containing 5.0 PTB of (c) alone and 5.0 PTB of (g) alone.

Similar results are obtained when a diesel fuel composition containing 1.0 PTB of (c) and 4.0 PTB of (g) is compared to diesel fuel compositions containing 5.0 PTB of (0) alone and 5.0 PTB of (g) alone.

EXAMPLE III A jet fuel composition containing 1.0 PTB of the condensation product of 1 mole of 2-hexylterephthalic acid and 2 moles of N,N-dibutyl 1,4-diamino-Z-ethylcyclohex- 5-ene (d) and 4.0 PTB of the condensation product of 1 mole of dimer acid, 1 mole of N-p-tolyl nonenylenediamine and 1 mole of N-(S-aminooctyl) imidazole (h) is prepared. When the composition is subjected to the Colonial Pipe Line Rust Test, it is found to have better anti-corrosion properties than jet fuel compositions containing 5.0 PTB of (d) alone and 5.0 PTB of (h) alone.

EXAMPLE IV A diesel fuel composition containing 4.0 PTB of the condensation product of 1 mole of 1,8-dicarboxyoct-4-ene and 2 moles of N,N-diisopropyl p-phenylenediamine (e) and 1.0 PTB of the condensation product of 1 mole of 1,18-dicarboxyoctadecane, 1 mole of N-phenyl, 1,4-diaminohexane and 1 mole of N-(p-aminophenyl) tetrahydropyrimidine (i) is prepared and its anti-corrosion properties determined by the Colonial Pipe Line Rust Test. The steel test piece has a lower percentage of surface rust than do steel test pieces from the same test on diesel fuel compositions containing 5.0 PTB of (e) alone and 5.0 PTB of (i) alone.

EXAMPLE V A No. 2 fuel oil composition containing 2.0 PTB of the condensation product of 1 mole of pimelic acid and 2 moles of N-methyl-N-butyl ethylenediamine (f) and 3.0 PTB of the condensation product of 1 mole of 1,4-dicarboxy-2-decylcyclohex-5-ene, 1 mole of N-naphthyl pphenylenediamine and 1 mole of N-(Z-aminoethyl) pyrazole (j) is prepared and subjected to the Colonial Pipe Line Rust Test. This No. 2 fuel oil composition is found to have better anti-corrosion properties than No. 2 fuel oil compositions containing 5.0 PTB of (f) alone and 5.0 PTB of (j) alone.

EXAMPLE VI A jet fuel composition containing 0.5 PTB of diamide (c) and 0.5 PTB of diamide (h) is prepared and subjected to the Colonial Pipe Line Rust Test. The steel test piece has less surface rust than do steel test pieces from tests run on a jet fuel composition containing 1.0 PTB of (c) alone and a jet fuel composition containing 1.0 PTB of (h) alone.

Similar results are obtained when a jet fuel composition containing 1.0 PTB of (c) and 1.0 PTB of (h) is compared to jet fuel compositions containing 2.0 PTB of (c) alone and compositions containing 2.0 PTB of (h) alone.

EXAMPLE VII A No. 2 fuel oil composition containing 0.75 PTB of diamide (e) and 7.25 PTB of diamide (g) is prepared.

7 This No. 2 fuel oil composition containing the additive mixture of this invention, when subjected to the Colonial Pipe Line Rust Test, is found to have better anti-corrosion properties than a N0. 2 fuel oil composition containing 8.0 PTB of diamide (e) alone and a No. 2 fuel oil composition containing 8.0 PTB of diamide (g) alone.

EXAMPLE VIII A diesel fuel composition containing 2.0 PTB of diamide (f) and 1.0 PTB of diamide (i) is prepared and its anti-corrosion properties determined by the Colonial Pipe Line Rust Test. The steel test piece has less surface rust than do steel test pieces from tests run on a diesel fuel composition containing 3.0 PTB of (f) alone and a diesel fuel composition containing 3.0 PTB of (i) alone.

EXAMPLE IX A jet fuel composition containing 7.0 PTB of diamide (d) and 1.0 PTB of diamide (j) is prepared and subjected to the Colonial Pipe Line Rust Test. It is found to have better anti-corrosion properties than a jet fuel composition containing 8.0 PTB of ((1) alone and a jet fuel composition containing 8.0 PTB of (j) alone.

While the invention has been described above with respect to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention.

We claim: 1. A distillate hydrocarbon fuel oil composition comprising:

(a) a major proportion of a distillate hydrocarbon fuel oil; and (b) a minor proportion of an anti-corrosion additive comprising:

(1) a diamide having the formula 1)2 2) l i]ii-NH-( z)-N( 1):

wherein R is an alkyl of 1 to 5 carbons, R is a hydrocarbylene of 1 to 10 carbons and D is a hydrocarbylene of 3 to 45 carbons; and

(2) a diamide having the formula wherein Ar and Ar are selected from the group consisting of aryl, alkaryl, and aralkyl groups of 6 to carbons and additionally one of Ar or Ar is hydrogen, R is a hydrocarbylene of l to 10 carbons, D is a hydrocarbylene of 3 to 45 carbons, R is a hydrocarbylene of 1 to 10 carbons,

is selected from the group consisting of 5 and 6 membered heterocyclic rings containing 2 ring nitrogens, and the weight ratio of diamide (l) to diamide (2) is from about 1:10 to about 10:1.

2. The composition of claim 1 wherein the distillate hydrocarbon fuel oil is selected from the group consisting of light burner fuel oil, diesel fuel and jet fuel.

3. The composition of claim 2 wherein R R and R are hydrocarbylenes of 2 to 8 carbons; D and D are hydrocarbylenes of 8 to 38 carbons and is selected from the group consisting of imidazole, pyrazole, imidazoline, tetrahydropyrimidine, hexadropyrimidine and piperazine groups.

4. The composition of claim 2 wherein the anti-corrosion additive mixture is present in an amount of from 8 about 0.5 to about 8 pounds per thousand barrels of said composition.

5. The composition of claim 4 wherein the weight ratio of the diamide having the formula to the diamide having the formula is from about 1:4 to about 4: 1.

6. The composition of claim 3 wherein the anti-corrosion additive mixture is present in an amount of from about 1 to about 5 pounds per thousand barrels of said composition.

7. The composition of claim 6 wherein the weight ratio of the diamide having the formula (R1)2 2)NH i[D1]( i1 U1 R I I R.) wherein R is an alkyl of 1 to 5 carbons, R is a hydrocarbylene of 1 to 10 carbons and D is a hydrocarbylene of 3 to 45 carbons; and

(b) a diamide having the formula wherein Ar and Ar are selected from the group consisting of aryl, alkaryl and aralkyl groups of 6 to 30 carbons and additionally one of Ar or Ar is hydrogen, R is a hydrocarbylene of 1 to 10 carbons, D is a hydrocarbylene of 3 to 45 carbons, R is a hydrocarbylene of 1 to 10' carbons,

is selected from the group consisting of 5 to 6 membered heterocyclic rings containing 2 ring nitrogens,

and the weight ratio of diamide (a) to diamide (b) is from about 1:10 to about 10:1.

10. The composition of claim 9 wherein R R and R are hydrocarbylenes of 2 to 8 carbons; D and D are bydrocarbylenes of 8 to 38 carbons and is selected from the group consisting of imidazole, pyrazole, imidazoline, tetrahydropyrimidine, hexahydropyrimidine and piperazine groups.

11. The composition of claim 9 wherein the Weight ratio of the diamide of (a) to the diamide of (b) is from about 1:4 to about 4: 1.

12. The composition of claim 10 wherein the weight ratio of the diamide of (a) to the diamide of (b) is from about 1:2 to about 2:1.

13. The composition of claim 12 wherein the diamide of (a) is obtained by condensing 1 mole of a dimerized polyunsaturated monocarboxylic fatty acid of 18 carbons with 2 moles of N,N-dimethyl propylenediamine and the diamide of (b) is obtained by condensing 1 mole of a dimerized polyunsaturated monocarboxylic fatty acid of 18 carbons with 1 mole of N-phenyl propylenediamine and 1 mole of N-(3-aminopropy1) piperazine.

References Cited UNITED STATES PATENTS DANIEL E. WYMAN, Primary Examiner W. J. SHINE, Assistant Examiner us. :1. X.'R. 44-66, 71; 252-392 

